| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 5514952 | Pesticide Biochemistry and Physiology | 2017 | 11 Pages |
•In bioassay of temephos derivatives on Xanthogaleruca luteola larvae, some compounds showed insecticidal properties.•Enzymatic properties of AChE in X. luteola and inhibitory mechanism by some temephos derivatives were investigated.•The electronic features such as high energy level-fill orbital(EHOMO) and low energy level-empty orbital(ELUMO) had the greatest impact on the potential insecticidal temephos derivative compounds..
Insect acetylcholinesterase (AChE) is the principal target for organophosphate (OP) and carbamate (CB) insecticides. In this research, an AChE from third instar larvae of elm left beetle, Xanthogaleruca luteola was purified by affinity chromatography. The enzyme was purified 75.29-fold with a total yield of 8.51%. As shown on denaturing SDS-PAGE, the molecular mass of purified AChE was 70 kDa. The enzyme demonstrated maximum activity at pH 7 and 35 °C. Furthermore, a series of temephos (Tem) derivatives with the general structure of P(O)XP(O) (1–44) were prepared, synthesized and characterized by 31P, 13C, 1H NMR and FT–IR spectral techniques. The toxicity of 36 new Tem derivatives was screened on the third instar larvae and the compound compound 1,2 cyclohexane-N,N′-bis(N,N′-piperidine phosphoramidate) exhibited the highest insecticidal potential. The method of kinetic analysis is applied in order to obtain the maximum velocity (Vmax), the Michaelis constant (Km) and the parameters characterizing the inhibition type for inhibitors with > 75% mortality in preliminary bioassay. The inhibition mechanism was mixed and inhibitory constant (Ki) was calculated as 4.70 μM− 1 min− 1 for this compound. Quantitative structure-activity relationship (QSAR) equations of these compounds indicated that the electron orbital energy has major effect on insecticidal properties.
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